1993 Volume 35 Issue 3 Pages 257-263
We observed that administration of exogenous glycerol reduces β-ATP level and increases glycerophosphate level using magnetic resonance spectroscopy (MRS) of the kidney. A new "glycerol-loading test" for use with MRS in rats was developed. Sprague-Dawley rats were anesthetized and the left kidney was exposed and placed on surface coil. 31P-MRS (109.25MHz) of the kidney was performed using 10μsec, 90' pulse width and 2.308 sec repetition time with an accumulation of 200 times. MRS was performed 24 hours after induction of acute renal failure in each model of acute renal failure. Glycerol-loading test was performed by the intravenous infusion of 10% glycerol through jugular vein over a 60 min period. MRS was recorded every 10 min during glycerol infusion and for 60 min after cessation of infusion. In normal rats, β-ATP level in the kidney was decreased to 52.0% of the pre-loading value at 55 min glycerol infusion and recovered to 66.7% 55 min after glycerol infusion was stopped. In the cisplatinum model, the reduction of β-ATP and the increase of glycerophosphate levels following glycerol-loading was similar to that in normal rats; however, the recovery of β-ATP level after infusion was stopped was weaker. Rats treated with glycerol and HgC12 showed rather severe acute renal failure, but the β-ATP level at 55 min glycerol infusion was 87.3% and 92.4%, respectively, showing difference from that in normal rats. No uptake of glycerol was observed 3 hours after 45 min pedicle clamping. These results revealed that even when the MRS pattern in groups of rats is similar before glycerol-loading test, glycerol infusion affects it under some conditions and not under others. Furthermore, the recovery pattern may be affected by some conditions. This glycerol-loading test may therefore be useful in the evaluation of intracellular energy metabolism with renal 31P-MRS.
